The present invention relates to the field of needled textile structures and it relates more particularly to a device for automatically feeding a circular type needling machine with a textile strip.
In a circular type needling machine, the annular preform for needling is placed on a needling table and is rotated by drive means, usually friction drive means, with which it is continuously in contact. That type of machine is fed flat level with the needling table from a strip of material for needling that is taken from unwinding apparatus external to the needling machine. Such flat feed nevertheless gives rise to a particular difficulty, especially when preforms are to be produced automatically without manual intervention.
The present invention thus sets out to solve this specific problem with a needling machine that includes an automatic feeder device. An object of the invention is also to provide such a device without significantly altering the overall size of a circular type needling machine.
These objects are achieved by a machine for needling a textile structure built up from a wound strip of material to be needled that is delivered by strip supply means, wherein said strip supply means comprise a storage drum containing said wound strip of textile material, an unwinding assembly for continuously extracting said strip from said storage drum, and a helical chute or xe2x80x9ctwistxe2x80x9d for taking up said extracted strip unwound from said drum and for bringing it up to a needling table where there are friction drive means. Said storage drum and said helical chute have the same axis C as said needling table.
Thus, with this particular structure, it is possible to feed textile material easily and automatically while conserving the same floor space or xe2x80x9cfootprintxe2x80x9d for the needling machine. In addition, the strip is well guided all the way to the needling table.
The helical chute for feeding said unwound strip of textile material to said needling table is secured to the frame of the machine and comprises two successive portions separated by a gap to allow cutting means to pass to cut said unwound strip.
The unwound strip of textile material is kept in contact with said helical chute while it is being fed to said needling table by two separate drive assemblies disposed respectively upstream and downstream from said means for cutting said strip.
Downstream from said downstream drive assembly, the machine preferably further includes a jockey roller hinged to said frame and designed to guarantee regular tension on said unwound strip of textile material after it has been cut by said cutting means and before it is taken up on said needling table by said friction drive means.
Each drive assembly comprises wheels placed one after another so as to fit closely to the helical shape of said feed chute for said unwound strip of textile material.
Advantageously, each drive assembly has at least two wheels each mounted on a support secured to said frame and connected to one another by a drive belt, at least one of said wheels in each assembly being connected to a motor and gear box unit by means of a universal joint.
In a preferred embodiment, the assembly device for unwinding said wound strip of textile material includes a plurality of conical rollers rotated by friction from a ring centered on wheels secured to said frame and rotated by a belt driven by a motor, and on which said wound strip of textile material rests once said storage drum has been installed on said machine. It may further include a presser roller held against one of said conical drive rollers by a resilient element acting in traction so as to enable a free end of said unwound strip of textile material to be taken up and guided towards said helical chute.
The storage drum includes a central hub rotating about an axis of rotation having a reception tray fixed to the bottom portion thereof (bottom of the drum), which reception tray is provided with openings for receiving said conical rollers for driving said wound strip of textile material.